Peah 7:2: An olive tree that stands between three rows of two rectangles [of grain], and one forgets it, it is not [subject to] Shikhechah. An olive tree that has two Seah [a specific unit of volume] [of olives remaining] in it, and he forgets it, it is not [subject to] Shikhechah. Regarding when did they say this? When he did not start [picking] it, but if he started, even the olive tree of Netufah in its time, and he forgets it, it is [subject to] Shikhechah. Any time that [the law of Shikhechah]
applies under it [the tree], it applies at the top of it; Rabbi Meir says: This
is only when the olive-beater has moved on.

Peah 7:3: Which is Peret? That which falls at the time of the grape
harvest. If one was harvesting grapes, and he was pricked by the cluster or was
entangled in leaves, and [grapes] fell from his hand to the earth and were
separated into single grapes, this belongs to the property owner. If one leaves
a basket under the vine, at the time that he harvests grapes, he is stealing
from the poor. Regarding this it is said, “Do not withdraw the border of those
who go up [to glean].” (Proverbs 22:28)